The ultimate and continuing objective of this research is the understanding of the pathogenesis of acne in order to improve preventive and therapeutic measures. During the current year our research goals include: 1. Continued study of the significance of the ratio of delta 5,8- to delta 9,12-octadecadienoic acids. 2. Measurement of the biosynthetic pathways in the sebaceous glands contained in the recipient site biopsies from patients undergoing hair transplants. 3. Measurements of the microflora and lipid composition in patients being treated with antibiotics. 4. Measurement of sebum composition in relation to dietary deprivation. 5. Electron microscopy of the pathologic changes in acne.